HFC systems have been and continue to be deployed to meet the ever-increasing demand for high-speed communications. Upgrading the existing and planned HFC systems to provide for new and additional services such as high data rate connection, which support Gigabit-Ethernet (GbE) to a Local Area Network (LAN), or a passive optical network that serves a number of customers is problematical. HFC systems/architectures use the Data Over Cable Service Interface Standard (DOCSIS) for data services. Due to constraints imposed by the coax portion of the HFC infrastructure, DOCSIS provides limited upstream capability (from the customer to the central office). This translates to limited upstream capacity that is extremely reliant on RF technology.
While power-splitting passive-optical networks (PS-PONs) are not reliant upon RF technology, they also have a limited capacity, as both the upstream and downstream channels must be shared (typically using Time-Division Multiplexing (TDM)), which can limit the bit-rate available to customers. See the FSAN standard, ITU Standard: (G.983.1).
Both HFC and PS-PONs carry the same downstream signals to multiple customers. Beyond the first node of the system multiple paths are typically used. In a PS-PON, the first node is a passive splitter and the multiple paths are multiple fibers. These fibers carry signals to additional splitters, or to optical-network units (ONUs), where optical-to-electronic conversion takes place. In a typical HFC architecture the first node is a fiber-node, where the optical signal is converted into an electronic signal, and carried over multiple coax buses for distribution throughout a neighborhood. In some instances the fiber-node will only serve a single coax bus. In a recently demonstrated HFC architecture, known as LightWire™ the first node is a Mux-Node, containing an optical splitter. Downstream signals are split, and carried over multiple fibers to mini-fiber-nodes, where the optical-to-electronic conversion takes place. In another HFC architecture, known as Oxiom, nodes are “daisy-chained” together. In these nodes, referred to as Ox-nodes, part of the optical power carrying the downstream signal is tapped off, converted to an electronic signal and sent via coax to customers, the remaining optical power continues to the next Ox-node in the “daisy chain”. Therefore, in the Oxiom architecture the downstream signals are carried to multiple customers via paths comprising both coax and fiber.
These and other problems have been overcome by the present invention.